A376500 Primes that contain at least one even digit and two different odd digits where any permutation of the odd digits leaving the even digits fixed produces a prime.
107, 149, 167, 239, 293, 347, 389, 419, 491, 613, 619, 631, 691, 701, 709, 743, 761, 769, 907, 941, 967, 983, 1009, 1013, 1019, 1031, 1049, 1063, 1091, 1123, 1223, 1229, 1249, 1289, 1321, 1429, 1487, 1499, 1609, 1627, 1669, 1823, 1847, 2113, 2131, 2143, 2237, 2239, 2273, 2293, 2309, 2311, 2341
Offset: 1
Examples
1013 is a term since the permutations of the odd digits that leave the even digits fixed give 1031 and 3011, which are also prime.
Links
- Robert Israel, Table of n, a(n) for n = 1..10000
Programs
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Maple
filter:= proc(n) local L,oddi,eveni,xeven,i; if not isprime(n) then return false fi; L:= convert(n,base,10); if member(5,L) then return false fi; oddi,eveni:= selectremove(t -> L[t]::odd,[$1..nops(L)]); if nops(eveni) = 0 or nops(convert(L[oddi],set))<2 then return false fi; xeven:= add(10^(i-1)*L[i],i=eveni); andmap(t -> isprime(xeven+add(10^(oddi[i]-1)*L[t[i]],i=1..nops(oddi))), combinat:-permute(oddi)) end proc: select(filter, [seq(i,i=3..10000,2)]); # Robert Israel, Oct 23 2024
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